1 hour agoWASHINGTON (AFP) — Democratic presidential nominee Barack Obama on Monday blamed Republicans for the "most serious financial crisis" since the 1930s after Wall Street debt woes sent global markets into meltdown.Republican candidate John McCain meanwhile blamed a faulty patchwork of regulatory oversight for causing shocks like the Lehman Brothers bankruptcy which forced central banks to pump billions into the money markets."The challenges facing our financial system today are more evidence that too many folks in Washington and on Wall Street weren't minding the store," Obama said in a statement."Eight years of policies that have shredded consumer protections, loosened oversight and regulation, and encouraged outsized bonuses to CEOs while ignoring middle-class Americans have brought us to the most serious financial crisis since the Great Depression," he said.Squarely blaming Republican President George W. Bush's administration for the crisis, Obama warned "this turmoil is a major threat to our economy and its ability to create good-paying jobs and help working Americans pay their bills, save for their future, and make their mortgage payments."McCain called the bankruptcy of Lehman Brothers "the latest reminder of ineffective regulation and management."Ensuring the United States remains the world's pre-eminent financial market would be the "highest priority" of a McCain administration, he said in a statement."In order to do this, major reform must be made in Washington and on Wall Street. We cannot tolerate a system that handicaps our markets and our banks and places at risk the savings of hard-working Americans and investors."He said his administration would "replace the outdated and ineffective patchwork quilt of regulatory oversight in Washington and bring transparency and accountability to Wall Street. We will rebuild confidence in our markets and restore our leadership in the financial world."The statements came after US investment giant Lehman Brothers declared itself bankrupt and Wall Street rival Merrill Lynch had to be taken over in a new financial earthquake that sent global markets into a slump.Lehman Brothers said it would file for bankruptcy on Monday after a frantic weekend of negotiations failed to arrange a rescue.In the fallout, Bank of America took over Merrill Lynch in a 50 billion dollar deal, insurance giant AIG was reported to have sought a massive emergency loan to head off its own crisis and a group of banks set up a 70-billion-dollar global emergency fund.The US Federal Reserve, European Central Bank and Bank of England injected tens of billions of dollars into money markets after the fall of the banking titans under the weight of the massive financing of bad loans.